How to use verify method of ExpectationGroup class

...7import Foundation8import XCTest9/// Enforce the relative order of invocations.10///11/// Calls to `verify` within the scope of an `inOrder` verification block are checked relative to12/// each other.13///14///     // Verify that `canFly` was called before `fly`15///     inOrder {16///       verify(bird.canFly).wasCalled()17///       verify(bird.fly()).wasCalled()18///     }19///20/// Pass options to `inOrder` verification blocks for stricter checks with additional invariants.21///22///     inOrder(with: .noInvocationsAfter) {23///       verify(bird.canFly).wasCalled()24///       verify(bird.fly()).wasCalled()25///     }26///27/// An `inOrder` block is resolved greedily, such that each verification must happen from the oldest28/// remaining unsatisfied invocations.29///30///     // Given these unsatisfied invocations31///     bird.canFly32///     bird.canFly33///     bird.fly()34///35///     // Greedy strategy _must_ start from the first `canFly`36///     inOrder {37///       verify(bird.canFly).wasCalled(twice)38///       verify(bird.fly()).wasCalled()39///     }40///41///     // Non-greedy strategy can start from the second `canFly`42///     inOrder {43///       verify(bird.canFly).wasCalled()44///       verify(bird.fly()).wasCalled()45///     }46///47/// - Parameters:48///   - options: Options to use when verifying invocations.49///   - block: A block containing ordered verification calls.50public func inOrder(with options: OrderedVerificationOptions = [],51                    file: StaticString = #file, line: UInt = #line,52                    _ block: () -> Void) {53  createOrderedContext(at: SourceLocation(file, line), options: options, block: block)54}55/// Additional options to increase the strictness of `inOrder` verification blocks.56public struct OrderedVerificationOptions: OptionSet {57  public let rawValue: Int58  public init(rawValue: Int) {59    self.rawValue = rawValue60  }61  62  /// Check that there are no recorded invocations before those explicitly verified in the block.63  ///64  /// Use this option to disallow invocations prior to those satisfying the first verification.65  ///66  ///     bird.name67  ///     bird.canFly68  ///     bird.fly()69  ///70  ///     // Passes _without_ the option71  ///     inOrder {72  ///       verify(bird.canFly).wasCalled()73  ///       verify(bird.fly()).wasCalled()74  ///     }75  ///76  ///     // Fails with the option77  ///     inOrder(with: .noInvocationsBefore) {78  ///       verify(bird.canFly).wasCalled()79  ///       verify(bird.fly()).wasCalled()80  ///     }81  public static let noInvocationsBefore = OrderedVerificationOptions(rawValue: 1 << 0)82  83  /// Check that there are no recorded invocations after those explicitly verified in the block.84  ///85  /// Use this option to disallow subsequent invocations to those satisfying the last verification.86  ///87  ///     bird.name88  ///     bird.canFly89  ///     bird.fly()90  ///91  ///     // Passes _without_ the option92  ///     inOrder {93  ///       verify(bird.name).wasCalled()94  ///       verify(bird.canFly).wasCalled()95  ///     }96  ///97  ///     // Fails with the option98  ///     inOrder(with: .noInvocationsAfter) {99  ///       verify(bird.name).wasCalled()100  ///       verify(bird.canFly).wasCalled()101  ///     }102  public static let noInvocationsAfter = OrderedVerificationOptions(rawValue: 1 << 1)103  104  /// Check that there are no recorded invocations between those explicitly verified in the block.105  ///106  /// Use this option to disallow non-consecutive invocations to each verification.107  ///108  ///     bird.name109  ///     bird.canFly110  ///     bird.fly()111  ///112  ///     // Passes _without_ the option113  ///     inOrder {114  ///       verify(bird.name).wasCalled()115  ///       verify(bird.fly()).wasCalled()116  ///     }117  ///118  ///     // Fails with the option119  ///     inOrder(with: .onlyConsecutiveInvocations) {120  ///       verify(bird.name).wasCalled()121  ///       verify(bird.fly()).wasCalled()122  ///     }123  public static let onlyConsecutiveInvocations = OrderedVerificationOptions(rawValue: 1 << 2)124}125private func getAllInvocations(in contexts: [UUID: MockingContext],126                               after baseInvocation: Invocation?) -> [Invocation] {127  return contexts.values128    .flatMap({ $0.allInvocations.value })129    .filter({130      guard let baseInvocation = baseInvocation else { return true }131      return $0.uid > baseInvocation.uid132    })133    .sorted(by: { $0.uid < $1.uid })134}135private func assertNoInvocationsBefore(_ capturedExpectation: CapturedExpectation,136                                       baseInvocation: Invocation?,137                                       contexts: [UUID: MockingContext]) throws {138  let allInvocations = getAllInvocations(in: contexts, after: baseInvocation)139  140  // Failure if the first invocation in all contexts doesn't match the first expectation.141  if let firstInvocation = allInvocations.first,142     !firstInvocation.isEqual(to: capturedExpectation.invocation) {143    let endIndex = allInvocations.firstIndex(where: {144      $0.isEqual(to: capturedExpectation.invocation)145    }) ?? allInvocations.endIndex146    let unexpectedInvocations = Array(allInvocations[allInvocations.startIndex..<endIndex])147    148    let failure = TestFailure.unexpectedInvocations(149      baseInvocation: capturedExpectation.invocation,150      unexpectedInvocations: unexpectedInvocations,151      priorToBase: true152    )153    throw ExpectationGroup.Failure(error: failure,154                                   sourceLocation: capturedExpectation.expectation.sourceLocation)155  }156}157private func assertNoInvocationsAfter(_ capturedExpectation: CapturedExpectation,158                                      baseInvocation: Invocation?,159                                      contexts: [UUID: MockingContext]) throws {160  let allInvocations = getAllInvocations(in: contexts, after: baseInvocation)161  guard !allInvocations.isEmpty else { return }162  163  let failure = TestFailure.unexpectedInvocations(164    baseInvocation: capturedExpectation.invocation,165    unexpectedInvocations: allInvocations,166    priorToBase: false167  )168  throw ExpectationGroup.Failure(error: failure,169                                 sourceLocation: capturedExpectation.expectation.sourceLocation)170}171private struct Solution {172  let firstInvocation: Invocation?173  let lastInvocation: Invocation?174  175  enum Failure: Error {176    case unsatisfiable177  }178}179private func satisfy(_ capturedExpectations: [CapturedExpectation],180                     at index: Int = 0,181                     baseInvocation: Invocation? = nil,182                     contexts: [UUID: MockingContext],183                     options: OrderedVerificationOptions) throws -> Solution {184  let capturedExpectation = capturedExpectations[index]185  let allInvocations = findInvocations(in: capturedExpectation.mockingContext,186                                       with: capturedExpectation.invocation.selectorName,187                                       before: nil,188                                       after: baseInvocation)189  var nextInvocationIndex = 1190  191  while true {192    if options.contains(.onlyConsecutiveInvocations), baseInvocation != nil {193      try assertNoInvocationsBefore(capturedExpectation,194                                    baseInvocation: baseInvocation,195                                    contexts: contexts)196    }197    do {198      // Try to satisfy the current expectations.199      let allInvocations = try expect(capturedExpectation.mockingContext,200                                      handled: capturedExpectation.invocation,201                                      using: capturedExpectation.expectation,202                                      before: allInvocations.get(nextInvocationIndex),203                                      after: baseInvocation)204      guard index+1 < capturedExpectations.count else { // Found a solution!205        return Solution(firstInvocation: allInvocations.first, lastInvocation: allInvocations.last)206      }207      208      // Potential match with the current base invocation, try satisfying the next expectation.209      let allMatchingInvocations = allInvocations.filter({ $0.isEqual(to: capturedExpectation.invocation) })210      let result = try satisfy(capturedExpectations,211                               at: index+1,212                               baseInvocation: allMatchingInvocations.first,213                               contexts: contexts,214                               options: options)215      216      // Check if still satisfiable when using the next invocation as a constraint.217      if let nextBaseInvocation = result.firstInvocation {218        try expect(capturedExpectation.mockingContext,219                   handled: capturedExpectation.invocation,220                   using: capturedExpectation.expectation,221                   before: nextBaseInvocation,222                   after: baseInvocation)223      }224      225      return Solution(firstInvocation: allInvocations.first, lastInvocation: result.lastInvocation)226    } catch let error as ExpectationGroup.Failure { // Propagate the precondition failure.227      throw error228    } catch { // Unable to satisfy the current expectation.229      guard nextInvocationIndex+1 <= allInvocations.count else {230        throw Solution.Failure.unsatisfiable // Unable to grow the window further.231      }232      nextInvocationIndex += 1 // Grow the invocation window.233    }234  }235}236/// Internal helper for `inOrder` verification scopes.237///   1. Creates an attributed `DispatchQueue` scope which collects all verifications.238///   2. Checks invocations on each mock using the provided `options`.239func createOrderedContext(at sourceLocation: SourceLocation,240                          options: OrderedVerificationOptions,241                          block scope: () -> Void) {242  let group = ExpectationGroup { group in243    let contexts = group.expectations.reduce(into: [UUID: MockingContext]()) {244      (result, expectation) in245      result[expectation.mockingContext.identifier] = expectation.mockingContext246    }247    248    // Check for invocations prior to the first expectation's invocation(s).249    if options.contains(.noInvocationsBefore), let firstExpectation = group.expectations.first {250      try assertNoInvocationsBefore(firstExpectation, baseInvocation: nil, contexts: contexts)251    }252    253    do {254      let result = try satisfy(group.expectations, contexts: contexts, options: options)255      256      // Check for invocations after the last expectation's invocation(s).257      if options.contains(.noInvocationsAfter), let lastExpectation = group.expectations.last {258        try assertNoInvocationsAfter(lastExpectation,259                                     baseInvocation: result.lastInvocation,260                                     contexts: contexts)261      }262    } catch let error as ExpectationGroup.Failure {263      throw error // Propagate wrapped precondition error.264    } catch _ as Solution.Failure {265      // It's difficult to clearly determine which expectation is breaking the group, so instead266      // just throw an error at the group level instead.267      let allInvocations = getAllInvocations(in: contexts, after: nil)268      let failure = TestFailure.unsatisfiableExpectations(capturedExpectations: group.expectations,269                                                          allInvocations: allInvocations)270      throw ExpectationGroup.Failure(error: failure, sourceLocation: sourceLocation)271    } catch {272      fatalError("Unexpected error type") // This shouldn't happen.273    }274  }275  276  let queue = DispatchQueue(label: "co.bird.mockingbird.verify.inOrder")277  queue.setSpecific(key: ExpectationGroup.contextKey, value: group)278  queue.sync { scope() }279  280  do {281    try group.verify()282  } catch let error as ExpectationGroup.Failure {283    FailTest(String(describing: error),284             file: error.sourceLocation.file,285             line: error.sourceLocation.line)286  } catch {287    fatalError("Unexpected error type") // This shouldn't happen.288  }289}...

...26  struct Failure: Error {27    let error: TestFailure28    let sourceLocation: SourceLocation29  }30  func verify(context: ExpectationGroup? = nil) throws {31    if let parent = parent, context == nil {32      parent.addSubgroup(self)33    } else {34      try verificationBlock(self)35    }36  }37  38  private(set) var expectations = [CapturedExpectation]()39  func addExpectation(mockingContext: MockingContext,40                      invocation: Invocation,41                      expectation: Expectation) {42    expectations.append(CapturedExpectation(mockingContext: mockingContext,43                                            invocation: invocation,44                                            expectation: expectation))...

1let group = ExpectationGroup()2let expectation1 = group.expectation(description: "Expectation1")3let expectation2 = group.expectation(description: "Expectation2")4let expectation3 = group.expectation(description: "Expectation3")5let expectation4 = group.expectation(description: "Expectation4")6let expectation5 = group.expectation(description: "Expectation5")7let expectation6 = group.expectation(description: "Expectation6")8expectation1.fulfill()9expectation2.fulfill()10expectation3.fulfill()11expectation4.fulfill()12expectation5.fulfill()13expectation6.fulfill()14group.verify()15let group = ExpectationGroup()16let expectation1 = group.expectation(description: "Expectation1")17let expectation2 = group.expectation(description: "Expectation2")18let expectation3 = group.expectation(description: "Expectation3")19let expectation4 = group.expectation(description: "Expectation4")20let expectation5 = group.expectation(description: "Expectation5")21let expectation6 = group.expectation(description: "Expectation6")22expectation1.fulfill()23expectation2.fulfill()24expectation3.fulfill()25expectation4.fulfill()26expectation5.fulfill()27group.verify()28let group = ExpectationGroup()29let expectation1 = group.expectation(description: "Expectation1")30let expectation2 = group.expectation(description: "Expectation2")31let expectation3 = group.expectation(description: "Expectation3")32let expectation4 = group.expectation(description: "Expectation4")33let expectation5 = group.expectation(description: "Expectation5")34let expectation6 = group.expectation(description: "Expectation6")35expectation1.fulfill()36expectation2.fulfill()37expectation3.fulfill()38expectation4.fulfill()39expectation5.fulfill()40expectation6.fulfill()41group.verify()

1func testFunc() {2    let group = ExpectationGroup()3    let exp1 = group.expectation(description: "exp1")4    let exp2 = group.expectation(description: "exp2")5    let exp3 = group.expectation(description: "exp3")6    let exp4 = group.expectation(description: "exp4")7    let exp5 = group.expectation(description: "exp5")8    exp1.fulfill()9    exp2.fulfill()10    exp3.fulfill()11    exp4.fulfill()12    exp5.fulfill()13    group.verify()14}15func testFunc() {16    let group = ExpectationGroup()17    let exp1 = group.expectation(description: "exp1")18    let exp2 = group.expectation(description: "exp2")19    let exp3 = group.expectation(description: "exp3")20    let exp4 = group.expectation(description: "exp4")21    let exp5 = group.expectation(description: "exp5")22    exp1.fulfill()23    exp2.fulfill()24    exp3.fulfill()25    exp4.fulfill()26    exp5.fulfill()27    group.verify()28}29func testFunc() {30    let group = ExpectationGroup()31    let exp1 = group.expectation(description: "exp1")32    let exp2 = group.expectation(description: "exp2")33    let exp3 = group.expectation(description: "exp3")34    let exp4 = group.expectation(description: "exp4")35    let exp5 = group.expectation(description: "exp5")36    exp1.fulfill()37    exp2.fulfill()38    exp3.fulfill()39    exp4.fulfill()40    exp5.fulfill()41    group.verify()42}43func testFunc() {44    let group = ExpectationGroup()45    let exp1 = group.expectation(description: "exp1")46    let exp2 = group.expectation(description: "exp2")47    let exp3 = group.expectation(description: "exp3")48    let exp4 = group.expectation(description: "exp4")49    let exp5 = group.expectation(description: "exp5")

1import XCTest2class Test1: XCTestCase {3    func test1() {4        let exp = expectation(description: "test1")5        exp.fulfill()6        wait(for: [exp], timeout: 10)7    }8}9class Test2: XCTestCase {10    func test2() {11        let exp = expectation(description: "test2")12        exp.fulfill()13        wait(for: [exp], timeout: 10)14    }15}16let group = ExpectationGroup()17let test1 = Test1()18let test2 = Test2()19let testSuite = XCTestSuite(name: "testSuite")20testSuite.addTest(test1)21testSuite.addTest(test2)22XCTMain([testSuite])23group.verify()24	 Executed 2 tests, with 0 failures (0 unexpected) in 0.000 (0.000) seconds25	 Executed 2 tests, with 0 failures (0 unexpected) in 0.000 (0.000) seconds

1let group = ExpectationGroup()2let expectation1 = Expectation(description: "1")3let expectation2 = Expectation(description: "2")4group.add(expectation1)5group.add(expectation2)6expectation1.fulfill()7expectation2.fulfill()8group.verify()9let group = ExpectationGroup()10let expectation1 = Expectation(description: "1")11let expectation2 = Expectation(description: "2")12group.add(expectation1)13group.add(expectation2)14expectation1.fulfill()15expectation2.fulfill()16group.verify()17let group = ExpectationGroup()18let expectation1 = Expectation(description: "1")19let expectation2 = Expectation(description: "2")20group.add(expectation1)21group.add(expectation2)22expectation1.fulfill()23expectation2.fulfill()24group.verify()25let group = ExpectationGroup()26let expectation1 = Expectation(description: "1")27let expectation2 = Expectation(description: "2")28group.add(expectation1)29group.add(expectation2)30expectation1.fulfill()31expectation2.fulfill()32group.verify()33let group = ExpectationGroup()34let expectation1 = Expectation(description: "1")35let expectation2 = Expectation(description: "2")36group.add(expectation1)37group.add(expectation2)38expectation1.fulfill()39expectation2.fulfill()40group.verify()41let group = ExpectationGroup()42let expectation1 = Expectation(description: "1")43let expectation2 = Expectation(description: "2")44group.add(expectation1)45group.add(expectation2)46expectation1.fulfill()47expectation2.fulfill()48group.verify()49let group = ExpectationGroup()50let expectation1 = Expectation(description: "1")51let expectation2 = Expectation(description: "2")52group.add(expectation1)53group.add(expectation2)54expectation1.fulfill()55expectation2.fulfill()56group.verify()57let group = ExpectationGroup()58let expectation1 = Expectation(description: "1")59let expectation2 = Expectation(description: "2")60group.add(expectation1)61group.add(expectation2)62expectation1.fulfill()63expectation2.fulfill()64group.verify()

1let group = ExpectationGroup()2group.verify()3let group = ExpectationGroup()4group.verify()5Note: You can call verify() from any file, but you must call it from the same file it was created in. If you call verify() from a different file, the following error will be printed:6let group = ExpectationGroup()7group.verify()8let group = ExpectationGroup()9group.verify()10Note: You can call verify() from any file, but you must call it from the same file it was created in. If you call verify() from a different file, the following error will be printed:

1var group = ExpectationGroup()2group.verify()3var group = ExpectationGroup()4group.wait()5var group = ExpectationGroup()6group.wait(for: 1.0)7var group = ExpectationGroup()8group.wait(for: 1.0, enforceOrder: true)9var group = ExpectationGroup()10group.wait(for: 1.0, timeout: 10.0)11var group = ExpectationGroup()12group.wait(for: 1.0, timeout: 10.0, enforceOrder: true)

1import XCTest2class 1: XCTestCase {3    func testExample() {4        let group = ExpectationGroup()5        group.expectation(description: "test1") { expectation in6            DispatchQueue.main.asyncAfter(deadline: .now() + 2) {7                expectation.fulfill()8            }9        }10        group.expectation(description: "test2") { expectation in11            DispatchQueue.main.asyncAfter(deadline: .now() + 1) {12                expectation.fulfill()13            }14        }15        group.expectation(description: "test3") { expectation in16            DispatchQueue.main.asyncAfter(deadline: .now() + 3) {17                expectation.fulfill()18            }19        }20        group.verify(timeout: 4) { error in21            XCTAssertNil(error)22        }23    }24}25import XCTest26class ExpectationGroup {27    private var expectations = [XCTestExpectation]()28    func expectation(description: String, closure: @escaping (XCTestExpectation) -> Void) {29        let expectation = XCTestExpectation(description: description)30        expectations.append(expectation)31        closure(expectation)32    }33    func verify(timeout: TimeInterval, closure: @escaping (Error?) -> Void) {34        let expectation = XCTestExpectation(description: "verify")35        DispatchQueue.main.asyncAfter(deadline: .now() + timeout) {36            if self.fulfillCount == self.expectations.count {37                expectation.fulfill()38            } else {39                closure(NSError(domain: "ExpectationGroup", code: -1, userInfo: nil))40            }41        }42        wait(for: [expectation], timeout: timeout + 1)43    }44    @objc private func fulfillExpectation() {45    }46}

1import XCTest2class ExpectationGroup: XCTestCase {3    func testExpectationGroup() {4        let group = DispatchGroup()5        let expectation = expectation(description: "expectation")6        let expectation1 = expectation(description: "expectation1")7        let expectation2 = expectation(description: "expectation2")8        let expectation3 = expectation(description: "expectation3")9        let expectation4 = expectation(description: "expectation4")10        let expectation5 = expectation(description: "expectation5")11        let expectation6 = expectation(description: "expectation6")12        let expectation7 = expectation(description: "expectation7")13        let expectation8 = expectation(description: "expectation8")14        let expectation9 = expectation(description: "expectation9")15        let expectation10 = expectation(description: "expectation10")16        let expectation11 = expectation(description: "expectation11")17        let expectation12 = expectation(description: "expectation12")18        let expectation13 = expectation(description: "expectation13")19        let expectation14 = expectation(description: "expectation14")20        let expectation15 = expectation(description: "expectation15")21        let expectation16 = expectation(description: "expectation16")22        let expectation17 = expectation(description: "expectation17")23        let expectation18 = expectation(description: "expectation18")24        let expectation19 = expectation(description: "expectation19")25        let expectation20 = expectation(description: "expectation20")26        let expectation21 = expectation(description: "expectation21")27        let expectation22 = expectation(description: "expectation22")28        let expectation23 = expectation(description: "expectation23")29        let expectation24 = expectation(description: "expectation24")30        let expectation25 = expectation(description: "expectation25")31        let expectation26 = expectation(description: "expectation26")32        let expectation27 = expectation(description: "expectation27")33        let expectation28 = expectation(description: "expectation28")34        let expectation29 = expectation(description: "expectation29")35        let expectation30 = expectation(description: "expectation30")36        let expectation31 = expectation(description: "expectation31")37        let expectation32 = expectation(description: "expectation32")38        let expectation33 = expectation(description: "expectation33")39        let expectation34 = expectation(description: "expectation34")40        let expectation35 = expectation(description: "expectation35")

1import XCTest2import XCTestExpectationGroup3class Tests: XCTestCase {4    func testExample() {5        let expectationGroup = ExpectationGroup()6        let expectation1 = expectation(description: "expectation1")7        let expectation2 = expectation(description: "expectation2")8        let expectation3 = expectation(description: "expectation3")9        expectationGroup.add(expectation: expectation1)10        expectationGroup.add(expectation: expectation2)11        expectationGroup.add(expectation: expectation3)12        expectationGroup.verify()13    }14}15import XCTest16import XCTestExpectationGroup17class Tests: XCTestCase {18    func testExample() {19        let expectationGroup = ExpectationGroup()20        let expectation1 = expectation(description: "expectation1")21        let expectation2 = expectation(description: "expectation2")22        let expectation3 = expectation(description: "expectation3")23        expectationGroup.add(expectation: expectation1)24        expectationGroup.add(expectation: expectation2)25        expectationGroup.add(expectation: expectation3)26        expectationGroup.verify(timeout: 10)27    }28}29import XCTest30import XCTestExpectationGroup31class Tests: XCTestCase {32    func testExample() {33        let expectationGroup = ExpectationGroup()34        let expectation1 = expectation(description: "expectation1")35        let expectation2 = expectation(description: "expectation2")36        let expectation3 = expectation(description: "expectation3")37        expectationGroup.add(expectation: expectation1